proxygen
gmock-matchers.cc
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30 // Author: wan@google.com (Zhanyong Wan)
31 
32 // Google Mock - a framework for writing C++ mock classes.
33 //
34 // This file implements Matcher<const string&>, Matcher<string>, and
35 // utilities for defining matchers.
36 
37 #include "gmock/gmock-matchers.h"
38 #include "gmock/gmock-generated-matchers.h"
39 
40 #include <string.h>
41 #include <sstream>
42 #include <string>
43 
44 namespace testing {
45 
46 // Constructs a matcher that matches a const string& whose value is
47 // equal to s.
49  *this = Eq(s);
50 }
51 
52 // Constructs a matcher that matches a const string& whose value is
53 // equal to s.
55  *this = Eq(internal::string(s));
56 }
57 
58 // Constructs a matcher that matches a string whose value is equal to s.
60 
61 // Constructs a matcher that matches a string whose value is equal to s.
63  *this = Eq(internal::string(s));
64 }
65 
66 #if GTEST_HAS_STRING_PIECE_
67 // Constructs a matcher that matches a const StringPiece& whose value is
68 // equal to s.
70  *this = Eq(s);
71 }
72 
73 // Constructs a matcher that matches a const StringPiece& whose value is
74 // equal to s.
76  *this = Eq(internal::string(s));
77 }
78 
79 // Constructs a matcher that matches a const StringPiece& whose value is
80 // equal to s.
82  *this = Eq(s.ToString());
83 }
84 
85 // Constructs a matcher that matches a StringPiece whose value is equal to s.
87  *this = Eq(s);
88 }
89 
90 // Constructs a matcher that matches a StringPiece whose value is equal to s.
91 Matcher<StringPiece>::Matcher(const char* s) {
92  *this = Eq(internal::string(s));
93 }
94 
95 // Constructs a matcher that matches a StringPiece whose value is equal to s.
97  *this = Eq(s.ToString());
98 }
99 #endif // GTEST_HAS_STRING_PIECE_
100 
101 namespace internal {
102 
103 // Joins a vector of strings as if they are fields of a tuple; returns
104 // the joined string.
105 GTEST_API_ string JoinAsTuple(const Strings& fields) {
106  switch (fields.size()) {
107  case 0:
108  return "";
109  case 1:
110  return fields[0];
111  default:
112  string result = "(" + fields[0];
113  for (size_t i = 1; i < fields.size(); i++) {
114  result += ", ";
115  result += fields[i];
116  }
117  result += ")";
118  return result;
119  }
120 }
121 
122 // Returns the description for a matcher defined using the MATCHER*()
123 // macro where the user-supplied description string is "", if
124 // 'negation' is false; otherwise returns the description of the
125 // negation of the matcher. 'param_values' contains a list of strings
126 // that are the print-out of the matcher's parameters.
128  const char* matcher_name,
129  const Strings& param_values) {
130  string result = ConvertIdentifierNameToWords(matcher_name);
131  if (param_values.size() >= 1)
132  result += " " + JoinAsTuple(param_values);
133  return negation ? "not (" + result + ")" : result;
134 }
135 
136 // FindMaxBipartiteMatching and its helper class.
137 //
138 // Uses the well-known Ford-Fulkerson max flow method to find a maximum
139 // bipartite matching. Flow is considered to be from left to right.
140 // There is an implicit source node that is connected to all of the left
141 // nodes, and an implicit sink node that is connected to all of the
142 // right nodes. All edges have unit capacity.
143 //
144 // Neither the flow graph nor the residual flow graph are represented
145 // explicitly. Instead, they are implied by the information in 'graph' and
146 // a vector<int> called 'left_' whose elements are initialized to the
147 // value kUnused. This represents the initial state of the algorithm,
148 // where the flow graph is empty, and the residual flow graph has the
149 // following edges:
150 // - An edge from source to each left_ node
151 // - An edge from each right_ node to sink
152 // - An edge from each left_ node to each right_ node, if the
153 // corresponding edge exists in 'graph'.
154 //
155 // When the TryAugment() method adds a flow, it sets left_[l] = r for some
156 // nodes l and r. This induces the following changes:
157 // - The edges (source, l), (l, r), and (r, sink) are added to the
158 // flow graph.
159 // - The same three edges are removed from the residual flow graph.
160 // - The reverse edges (l, source), (r, l), and (sink, r) are added
161 // to the residual flow graph, which is a directional graph
162 // representing unused flow capacity.
163 //
164 // When the method augments a flow (moving left_[l] from some r1 to some
165 // other r2), this can be thought of as "undoing" the above steps with
166 // respect to r1 and "redoing" them with respect to r2.
167 //
168 // It bears repeating that the flow graph and residual flow graph are
169 // never represented explicitly, but can be derived by looking at the
170 // information in 'graph' and in left_.
171 //
172 // As an optimization, there is a second vector<int> called right_ which
173 // does not provide any new information. Instead, it enables more
174 // efficient queries about edges entering or leaving the right-side nodes
175 // of the flow or residual flow graphs. The following invariants are
176 // maintained:
177 //
178 // left[l] == kUnused or right[left[l]] == l
179 // right[r] == kUnused or left[right[r]] == r
180 //
181 // . [ source ] .
182 // . ||| .
183 // . ||| .
184 // . ||\--> left[0]=1 ---\ right[0]=-1 ----\ .
185 // . || | | .
186 // . |\---> left[1]=-1 \--> right[1]=0 ---\| .
187 // . | || .
188 // . \----> left[2]=2 ------> right[2]=2 --\|| .
189 // . ||| .
190 // . elements matchers vvv .
191 // . [ sink ] .
192 //
193 // See Also:
194 // [1] Cormen, et al (2001). "Section 26.2: The Ford-Fulkerson method".
195 // "Introduction to Algorithms (Second ed.)", pp. 651-664.
196 // [2] "Ford-Fulkerson algorithm", Wikipedia,
197 // 'http://en.wikipedia.org/wiki/Ford%E2%80%93Fulkerson_algorithm'
199  public:
200  explicit MaxBipartiteMatchState(const MatchMatrix& graph)
201  : graph_(&graph),
202  left_(graph_->LhsSize(), kUnused),
203  right_(graph_->RhsSize(), kUnused) {
204  }
205 
206  // Returns the edges of a maximal match, each in the form {left, right}.
208  // 'seen' is used for path finding { 0: unseen, 1: seen }.
209  ::std::vector<char> seen;
210  // Searches the residual flow graph for a path from each left node to
211  // the sink in the residual flow graph, and if one is found, add flow
212  // to the graph. It's okay to search through the left nodes once. The
213  // edge from the implicit source node to each previously-visited left
214  // node will have flow if that left node has any path to the sink
215  // whatsoever. Subsequent augmentations can only add flow to the
216  // network, and cannot take away that previous flow unit from the source.
217  // Since the source-to-left edge can only carry one flow unit (or,
218  // each element can be matched to only one matcher), there is no need
219  // to visit the left nodes more than once looking for augmented paths.
220  // The flow is known to be possible or impossible by looking at the
221  // node once.
222  for (size_t ilhs = 0; ilhs < graph_->LhsSize(); ++ilhs) {
223  // Reset the path-marking vector and try to find a path from
224  // source to sink starting at the left_[ilhs] node.
225  GTEST_CHECK_(left_[ilhs] == kUnused)
226  << "ilhs: " << ilhs << ", left_[ilhs]: " << left_[ilhs];
227  // 'seen' initialized to 'graph_->RhsSize()' copies of 0.
228  seen.assign(graph_->RhsSize(), 0);
229  TryAugment(ilhs, &seen);
230  }
231  ElementMatcherPairs result;
232  for (size_t ilhs = 0; ilhs < left_.size(); ++ilhs) {
233  size_t irhs = left_[ilhs];
234  if (irhs == kUnused) continue;
235  result.push_back(ElementMatcherPair(ilhs, irhs));
236  }
237  return result;
238  }
239 
240  private:
241  static const size_t kUnused = static_cast<size_t>(-1);
242 
243  // Perform a depth-first search from left node ilhs to the sink. If a
244  // path is found, flow is added to the network by linking the left and
245  // right vector elements corresponding each segment of the path.
246  // Returns true if a path to sink was found, which means that a unit of
247  // flow was added to the network. The 'seen' vector elements correspond
248  // to right nodes and are marked to eliminate cycles from the search.
249  //
250  // Left nodes will only be explored at most once because they
251  // are accessible from at most one right node in the residual flow
252  // graph.
253  //
254  // Note that left_[ilhs] is the only element of left_ that TryAugment will
255  // potentially transition from kUnused to another value. Any other
256  // left_ element holding kUnused before TryAugment will be holding it
257  // when TryAugment returns.
258  //
259  bool TryAugment(size_t ilhs, ::std::vector<char>* seen) {
260  for (size_t irhs = 0; irhs < graph_->RhsSize(); ++irhs) {
261  if ((*seen)[irhs])
262  continue;
263  if (!graph_->HasEdge(ilhs, irhs))
264  continue;
265  // There's an available edge from ilhs to irhs.
266  (*seen)[irhs] = 1;
267  // Next a search is performed to determine whether
268  // this edge is a dead end or leads to the sink.
269  //
270  // right_[irhs] == kUnused means that there is residual flow from
271  // right node irhs to the sink, so we can use that to finish this
272  // flow path and return success.
273  //
274  // Otherwise there is residual flow to some ilhs. We push flow
275  // along that path and call ourselves recursively to see if this
276  // ultimately leads to sink.
277  if (right_[irhs] == kUnused || TryAugment(right_[irhs], seen)) {
278  // Add flow from left_[ilhs] to right_[irhs].
279  left_[ilhs] = irhs;
280  right_[irhs] = ilhs;
281  return true;
282  }
283  }
284  return false;
285  }
286 
287  const MatchMatrix* graph_; // not owned
288  // Each element of the left_ vector represents a left hand side node
289  // (i.e. an element) and each element of right_ is a right hand side
290  // node (i.e. a matcher). The values in the left_ vector indicate
291  // outflow from that node to a node on the the right_ side. The values
292  // in the right_ indicate inflow, and specify which left_ node is
293  // feeding that right_ node, if any. For example, left_[3] == 1 means
294  // there's a flow from element #3 to matcher #1. Such a flow would also
295  // be redundantly represented in the right_ vector as right_[1] == 3.
296  // Elements of left_ and right_ are either kUnused or mutually
297  // referent. Mutually referent means that left_[right_[i]] = i and
298  // right_[left_[i]] = i.
299  ::std::vector<size_t> left_;
300  ::std::vector<size_t> right_;
301 
303 };
304 
306 
309  return MaxBipartiteMatchState(g).Compute();
310 }
311 
313  ::std::ostream* stream) {
314  typedef ElementMatcherPairs::const_iterator Iter;
315  ::std::ostream& os = *stream;
316  os << "{";
317  const char *sep = "";
318  for (Iter it = pairs.begin(); it != pairs.end(); ++it) {
319  os << sep << "\n ("
320  << "element #" << it->first << ", "
321  << "matcher #" << it->second << ")";
322  sep = ",";
323  }
324  os << "\n}";
325 }
326 
327 // Tries to find a pairing, and explains the result.
328 GTEST_API_ bool FindPairing(const MatchMatrix& matrix,
329  MatchResultListener* listener) {
331 
332  size_t max_flow = matches.size();
333  bool result = (max_flow == matrix.RhsSize());
334 
335  if (!result) {
336  if (listener->IsInterested()) {
337  *listener << "where no permutation of the elements can "
338  "satisfy all matchers, and the closest match is "
339  << max_flow << " of " << matrix.RhsSize()
340  << " matchers with the pairings:\n";
341  LogElementMatcherPairVec(matches, listener->stream());
342  }
343  return false;
344  }
345 
346  if (matches.size() > 1) {
347  if (listener->IsInterested()) {
348  const char *sep = "where:\n";
349  for (size_t mi = 0; mi < matches.size(); ++mi) {
350  *listener << sep << " - element #" << matches[mi].first
351  << " is matched by matcher #" << matches[mi].second;
352  sep = ",\n";
353  }
354  }
355  }
356  return true;
357 }
358 
359 bool MatchMatrix::NextGraph() {
360  for (size_t ilhs = 0; ilhs < LhsSize(); ++ilhs) {
361  for (size_t irhs = 0; irhs < RhsSize(); ++irhs) {
362  char& b = matched_[SpaceIndex(ilhs, irhs)];
363  if (!b) {
364  b = 1;
365  return true;
366  }
367  b = 0;
368  }
369  }
370  return false;
371 }
372 
373 void MatchMatrix::Randomize() {
374  for (size_t ilhs = 0; ilhs < LhsSize(); ++ilhs) {
375  for (size_t irhs = 0; irhs < RhsSize(); ++irhs) {
376  char& b = matched_[SpaceIndex(ilhs, irhs)];
377  b = static_cast<char>(rand() & 1); // NOLINT
378  }
379  }
380 }
381 
382 string MatchMatrix::DebugString() const {
383  ::std::stringstream ss;
384  const char *sep = "";
385  for (size_t i = 0; i < LhsSize(); ++i) {
386  ss << sep;
387  for (size_t j = 0; j < RhsSize(); ++j) {
388  ss << HasEdge(i, j);
389  }
390  sep = ";";
391  }
392  return ss.str();
393 }
394 
395 void UnorderedElementsAreMatcherImplBase::DescribeToImpl(
396  ::std::ostream* os) const {
397  if (matcher_describers_.empty()) {
398  *os << "is empty";
399  return;
400  }
401  if (matcher_describers_.size() == 1) {
402  *os << "has " << Elements(1) << " and that element ";
403  matcher_describers_[0]->DescribeTo(os);
404  return;
405  }
406  *os << "has " << Elements(matcher_describers_.size())
407  << " and there exists some permutation of elements such that:\n";
408  const char* sep = "";
409  for (size_t i = 0; i != matcher_describers_.size(); ++i) {
410  *os << sep << " - element #" << i << " ";
411  matcher_describers_[i]->DescribeTo(os);
412  sep = ", and\n";
413  }
414 }
415 
416 void UnorderedElementsAreMatcherImplBase::DescribeNegationToImpl(
417  ::std::ostream* os) const {
418  if (matcher_describers_.empty()) {
419  *os << "isn't empty";
420  return;
421  }
422  if (matcher_describers_.size() == 1) {
423  *os << "doesn't have " << Elements(1)
424  << ", or has " << Elements(1) << " that ";
425  matcher_describers_[0]->DescribeNegationTo(os);
426  return;
427  }
428  *os << "doesn't have " << Elements(matcher_describers_.size())
429  << ", or there exists no permutation of elements such that:\n";
430  const char* sep = "";
431  for (size_t i = 0; i != matcher_describers_.size(); ++i) {
432  *os << sep << " - element #" << i << " ";
433  matcher_describers_[i]->DescribeTo(os);
434  sep = ", and\n";
435  }
436 }
437 
438 // Checks that all matchers match at least one element, and that all
439 // elements match at least one matcher. This enables faster matching
440 // and better error reporting.
441 // Returns false, writing an explanation to 'listener', if and only
442 // if the success criteria are not met.
443 bool UnorderedElementsAreMatcherImplBase::
444 VerifyAllElementsAndMatchersAreMatched(
445  const ::std::vector<string>& element_printouts,
446  const MatchMatrix& matrix,
447  MatchResultListener* listener) const {
448  bool result = true;
449  ::std::vector<char> element_matched(matrix.LhsSize(), 0);
450  ::std::vector<char> matcher_matched(matrix.RhsSize(), 0);
451 
452  for (size_t ilhs = 0; ilhs < matrix.LhsSize(); ilhs++) {
453  for (size_t irhs = 0; irhs < matrix.RhsSize(); irhs++) {
454  char matched = matrix.HasEdge(ilhs, irhs);
455  element_matched[ilhs] |= matched;
456  matcher_matched[irhs] |= matched;
457  }
458  }
459 
460  {
461  const char* sep =
462  "where the following matchers don't match any elements:\n";
463  for (size_t mi = 0; mi < matcher_matched.size(); ++mi) {
464  if (matcher_matched[mi])
465  continue;
466  result = false;
467  if (listener->IsInterested()) {
468  *listener << sep << "matcher #" << mi << ": ";
469  matcher_describers_[mi]->DescribeTo(listener->stream());
470  sep = ",\n";
471  }
472  }
473  }
474 
475  {
476  const char* sep =
477  "where the following elements don't match any matchers:\n";
478  const char* outer_sep = "";
479  if (!result) {
480  outer_sep = "\nand ";
481  }
482  for (size_t ei = 0; ei < element_matched.size(); ++ei) {
483  if (element_matched[ei])
484  continue;
485  result = false;
486  if (listener->IsInterested()) {
487  *listener << outer_sep << sep << "element #" << ei << ": "
488  << element_printouts[ei];
489  sep = ",\n";
490  outer_sep = "";
491  }
492  }
493  }
494  return result;
495 }
496 
497 } // namespace internal
498 } // namespace testing
GTEST_API_ string ConvertIdentifierNameToWords(const char *id_name)
char b
internal::EqMatcher< T > Eq(T x)
::std::string string
Definition: gtest-port.h:1097
::std::ostream * stream()
StreamCodecFactory stream
#define GTEST_API_
Definition: gtest-port.h:934
GTEST_API_ bool FindPairing(const MatchMatrix &matrix, MatchResultListener *listener)
bool HasEdge(size_t ilhs, size_t irhs) const
const Graph * graph_
MaxBipartiteMatchState(const MatchMatrix &graph)
static const size_t kUnused
GTEST_API_ string JoinAsTuple(const Strings &fields)
::std::vector< ElementMatcherPair > ElementMatcherPairs
#define GTEST_DISALLOW_ASSIGN_(type)
Definition: gtest-port.h:869
std::unordered_set< std::pair< const IValidator *, const dynamic * > > seen
Definition: JSONSchema.cpp:92
static void LogElementMatcherPairVec(const ElementMatcherPairs &pairs,::std::ostream *stream)
def Iter(n, format, sep='')
bool TryAugment(size_t ilhs,::std::vector< char > *seen)
#define GTEST_CHECK_(condition)
Definition: gtest-port.h:1295
::std::pair< size_t, size_t > ElementMatcherPair
GTEST_API_ string FormatMatcherDescription(bool negation, const char *matcher_name, const Strings &param_values)
GTEST_API_ ElementMatcherPairs FindMaxBipartiteMatching(const MatchMatrix &g)
g_t g(f_t)
::std::vector< string > Strings
static set< string > s
Range< const char * > StringPiece